As part of that conference, two Service biologists are presenting a workshop designed to help wildlife biologists and other conservationists effectively communicate the best available science on the effects on wildlife from free-ranging domestic cats. The Service has no national policy concerning trap-neuter-release programs or feral cats.

I find it very strange that there would be not be an edit or review of the presentations done by employees/consultants (personnel on your payroll.) Quite frankly, I know of no organization that would allow taxpayer paid employees to present at a conference of this magnitude without a screening of materials to be presented. In fact, one could deem this type of policy quite irresponsible. Are you sure you meant that you do not review and screen presentations? Perhaps this was simply a poor choice in wording. "Do not necessarily represent the viewpoint" is a common phrase used to excuse positions for which one does not want direct attribution. There is a commonality of philosophy to be found in positions which are "presented" in past and current workshops. If there were no interest in presenting a specific viewpoint supported by U.S. Fish&Wildlife for current or upcoming policies, one can be quite certain no such presentation would be sponsored.

What a disappointment. I expect the FWS to be a leader in wildlife conservation and science. This position is both morally and scientifically indefensible. The science is in, there is no more debate needed on this issue: trap, neuter, release is not effective. Feral cats are invasive predators having major detrimental effects on native birds and other wildlife. What's the controversy?

Michael, you might be interested in Tom Will’s 2010 presentation to the Bird Conservation Alliance—in which he suggests otherwise:

“Is it still FWS policy to promote legislation banning feeding of wildlife? Yes. The U.S. Fish and Wildlife Service (Service) stands firmly behind its recommendations promoting legislation banning the feeding of wildlife, especially nuisance species such as feral cats. Local governments are better equipped than are Federal and State agencies to regulate feral and free-ranging cats since most local governments have ordinances in place to address domestic animal issues as well as animal control services and personnel to implement those ordinances.

Is it still FWS policy opposing free ranging cats and establishment of feral cat colonies? Yes. The Service continues to oppose the establishment of feral cat colonies as well as the perpetuation and continued operation of feral cat colonies.”

Will’s presentation (mentioned in my previous comment) is a gross misrepresentation of the data (done, I’m sure at taxpayer’s expense), a dramatic (though, sadly, not uncommon) failure of USFWS’s stated commitment to the “best available science.” Readers interested in the details are welcome to check out my blog, Vox Felina (http://www.voxfelina.com/2011/06/spoiler-alert/" target="_blank">http://www.voxfelina.com/2011/06/spoiler-alert/), where I’ve pointed out some of Will’s more egregious errors, and posted a link to his original presentation.

If we don't have a national policy of TNR, then we should. It has been documented to work. It has worked in my neighborhood as well. Steve, why don't you check out the research to see whether you can find any actual data supporting your claim that cats kill more wildlife than oilspills (or than human overpopulation and encroachment, for that matter). Let me know what you find, but I already know you won't find any hard data.

What's sad is that while cats are a devastating invasive in every state nothing pragmatic is being done to mitigate their impact.... meanwhile FWS spends taxpayer dollars to promote policy based on staff preference in the case of adding 9 constrictors to the injurious wildlife list. Burmese pythons struggle to survive in 3 counties in the southern tip of Florida and FWS is attempting to invoke Lacey Act. Cats are arguably the most damaging vertebrate predatory invader on the planet and FWS tiptoes because of the animal rights industry.

Perhaps if our earlier destruction of habitat hadn't taken such a toll on migratory songbird populations, and perhaps if people were better keepers of their pet cats, no one would need give a thought to the impact of stray cats on neighborhood wildlife. But just as stray dogs kill cats, stray cats kill birds. And no "trap, neuter, and release" program is going to stop that.

Perhaps a "No National Policy" now will create more jobs for listing biologist in the future. That way we can spend millions listing and protecting future endangered birds, thanks to Today's position on this issue.

Data is there to support the negative impact of TNR and ferral cats. What is lacking in FWS is having leadership to take a stand and take some heat for it.

Do what is right, take action now, save the birds, and avoid the need for listing species in the future!

As long as there are irresponsible pet owners who allow their cats to roam or who throw them out for some selfish reason instead of taking them to the shelter or finding a good home for them, there are going to be stray and feral cats - always. If we want to fix the stray and feral cat problem, I think we should get to the root cause of that problem - the pet owners - rather than trying to solve the problem by attacking the results. Instead of killing, teach pet owners the dangers of outdoor life for their cats or petition to have states pass laws to enforce owners to keep their cat indoors (excepting supervised walks on leashes) and not to abandon cats who are no longer wanted. I'm sure you'd have a lot of supporters for those petitions. Catch and send strays to shelters and send spayed/neutered ferals to sanctuaries where they are fed normal cat food and where birds can't get in (or cats out). After the old ferals dwindle out, you won't need sanctuaries either.

Common sense dictates that with an estimated 60 million feral cats in the U.S alone, and assuming that each cat kills at least one migratory bird (extrememly conservative assumption) per year, those numbers alone are higher than the number of birds killed in oil spills annually in the U.S which I would estimate are in the thousands at best. Feral cats are an invasive species that need to be removed just like any other invasive species.

Sadly, this is a case where hysteria is winning out over science. The Obama Administration made a commitment to making decisions based on the best science, but now they seem to be backing down in the face of public hysteria. The science in this case is very strong - feral cats have a devastating impact on native wildilfe. Sad to see the administration that said it was going to stand on science back down.

Interesting how everyone throws out these numbers about how many birds cats kill. Every reputable study I have ever read makes it clear that the actual number is unknown. In fact some of the studies that purport to document cat kills work by weighing a small bird with a tracking device. Like tying a 100 pound weight on a zebra.

Hawaii is an odd choice for this seminar. I would guess that most of our native species are located in only a few areas. We ARE overrun with invasive bird species as well as 3 introduced species of rats. Sure, you don't want cats living next to endangered species, but what happens to the invasive species population when you take their prime predator away?

Yes, having a national policy would allow us to speak with one voice. In the absence of that, Service biologists in the field have already gone on record opposed to TNR in favor of TNC (Trap Neuter Contain). I think the reason for no nation policy is less political and more that there are greater pressing issues eating the collective lunch.

Science, shmience! Compassion should rule. So many people, like myself, are fond of domestic cats, and ferals are often simply domestic cats that have been "dumped." We should as a country enlist volunteers to run a "spay, neuter, release" program, and others to manage the feral colonies. There are ways, aside from keeping these sentient animals fed, to deter birds from the areas where they might be injured.

I have worked in TNR of feral cats for many years. It works if done in a systematic way by those with training. The public needs to understand that U.S. Fish and Wildlife is a killing machine for wildlife that this agency deems "nuisance" at their whim, and all funded by our tax dollars. Their intended expansion into killing cats is just one more item on their list.

So on the one hand we are supposed to believe your success with TNR while you simultaneously bash the FWS. The agency responsible for the comeback of the bald eagle, peregrine falcon and whooping crane. Hopefully this forum will help FWS understand the extreme nature of the pro-TNR crowd.

Letting compassion rule will have severe detrimental impacts on native species. Refuges are charged with conserving native habitats and species using science. Cats are not native, and do not warrant protection on Refuge lands. FWS needs a national policy to deal with cats. When cat owners do not take responsibilty for their animals others will have to.

The concept of the U.S. Fish & Wildlife Service's involvement in the feral cat issue is chilling. Its procedures of poisoning, snaring, gassing, use of leghold traps and shooting of wildlife have been in question for years. Yet, the Wildlife Service continues to waste millions of taxpayer dollars killing wolves, mountain lions,geese, coyotes, foxes and many other thousands of animals, frequently as a subsidy for the livestock industry. The reassuring statement by F&W that "any findings or conclusions presented by Service employees are those of the organizers" is self explanatory. The Wildlife Society which promotes removal of free-rnging cats and elimination of feral colonies is that organizer Education of the public regarding pet care, ESTABLISHMENT OF SPAY AND NEUTER CLINICS, encouraging pet "owners" to keep their cats indoors thus protecting the animals and certainly enjoying them more is essential. Regulations should be set at a local level.

And so killing is the answer? I am sure that Fish and Wildlife is well aware of the numbers of feral cats that reside in the U.S. and all other countries on the globe. Even if there were enough workers and enough funding to kill all of these cats the job would be never ending. At least tnr controls some of the population by reducing new births. Until the public is educated and has access to low cost or free spay/neuter the problem will continue. It only takes a few people who don't want their cat, do not sterilize it and put it outside to start the process all over again. Killing is like an ostrich putting it's head in the sand, ignoring the obvious; that tnr may not be perfect or the final solution but killing is even less effective and very unpalatable. Birds die and disappear due more to chemicals and lack of habitat then from feral cats, studies notwithstanding. I also suspect that these studies are done by people with an interest that is not for the good of the cats.

Question for commenters who are convinced that feral cats are solely responsible for decreasing bird populations: where's your proof? I spent my lunch hour resarching this. I've only found proof (ie., research by qualified professionals) that urban sprawl is the #1 cause of decreasing bird species. I also located some Australian studies that proved that feral cats were only problematic when part of a small island's population. Research is free, folks. I suggest you try it.

Peer-reviewed science shows that birds are in crisis from forest fragmentation, climate change, and acid rain, not cats. And the birders don’t count bird numbers correctly.

1. University of Michigan biologists found that growth of Latin American coffee plantations destroys the shade cover and birds who winter there are not surviving because of that forest destruction 2. The Minnesota DNR found that over-development prevents “development avoiding” bird species from using the suburbs 3. A Science News article shows that forest fragmentation causes bird populations to become isolated and disconnected, Resulting inbred birds are weaker and more disease-prone4. Wildlife biologists in NY found that acid rain kills songbirds5. NC State researchers found that traditional means of estimating the abundance and diversity of bird species are flawed

The FWS is over-reacting to bird-lovers/cat-haters. They are ill-informed about addressing the real causes of bird number decreases.

As both a cat owner and ornithologist I am of the mindset that all domestic cats remain strictly indoors. I do this with both of my cats and with great success, no birds or other native wildlife die at the claws of my pets, which are my responsibility. Data or no data, to claim that cats don't cause declines (or insignificant declines) in songbird populations is just ignorance.

My own parents let their cats outdoors. As luck would have it, a great-horned owl took down one of their cats (birds fight back!) but the other one repeatedly brings back to the house orioles, bluebirds, robins, and doves. And he doesnt even eat them!

I am currently staying with friends in CO and they let their cat go out onto the porch on a leash. Great right? Well, he caught an adult rabbit the other day. Once again, if domestic cats can do this, I can only imagine what damage ferals do.

There is very little we can control, but we can try to control this, any relief for the birds helps.

Whatever one's view on TNR and feral cats is, it is a big stretch to say it is appropriate to use on an island in the presence of rare and endangered species (like the Florida Keys).Yes, there many other problems that face our country's wildlife. But the FWS's job is to manage Wildlife - and cats are not. It is entirely appropriate that they should not tolerate cats (or other detrimental exotic species)on lands that they manage.

What I find incredibly sad is that so many are willing to save birds but yet condemn cats to death. Why is that? TNR does work, unfortunately there will always be idiotic humans who let their cats outside or who dump friendly cats when they are no longer cute. All those of you here ready to kill cats why don't you stop writing on websites and do something proactive about it. Help the problem instead of complaining.

Lynne, as far as I know, no one has ever said feral cats are solely responsible for decline in migratory bird populations or species diversity. It's true, habitat loss and fragmention is a major cause in the declines of many wildlife species, including birds. However, when you add a non-native predator into an ecosystem that is already stressed, you can bet that negative impacts to resident biota will and do occur. Last time I checked cats were carnivores, and not eating split pea soup.

Just a reminder that feral cats have been identified as major threats to 8 small mammal species, 1 turtle, and 3 bird species in Florida alone. All these species are listed as Threatened or Endangered under the federal Endangered Species Act.

Hopefully, the rapid expansion of coyotes into surburban areas around the U.S will aid in helping reduce feral cat populations (a native predator is doing its intended job).

There's no credible evidence that feral cats decimate bird populations. Surely they kill some birds, but hundreds of millions? Such estimates of mass bird killing by cats are based on flawed methodology that would shame even a high school math student. There IS, however, ample evidence that TNR works, despite the wrong info in a USFWS factsheet saying TNR increases cat populations. In fact, the cornerstone of TNR is responsible colony management, which includes identifying tame cats and young, weaned kittens in a colony and removing them for adoption. And if we spay and neuter most feral cats, we'll definitely have fewer of them and therefore fewer birds will be killed by cats than there are now (however many that is). If you want to know who's killing birds, look at who's destroying their habitat and putting up condos. USFWS has no valid scientific reason not to have a policy promoting TNR.

To all commentators, particularly feral cat supporters, an excellent article in the Journal Conservation Biology is a must read, it should open your mind somewhat to the realty of TNR programs and ecological impacts feral cats have on native wildlife including birds. This is a peer reviewed Journal highly regarded by the professional conservationists.T. Loncore, C. Rich, and L. M. Sullivan. 2009. Critical assessment of claims regarding management of feral cats by trap–neuter–return. J. Conservation Biology 23(4):887-8

To those who oppose TNR (and by implication advocate the killing of feral cats):1. Just because your parents' cat killed many birds, it doesn't mean every cat is so successful. Also, predators are creatures of opportunity who kill sick and weak prey more often than not. 2. It is dangerous to talk of cats as "non-native" species. Want to get rid of a non-native species? Deport all people of European, African and Asian descent. While you're at it, kill off the house sparrows and starlings if nativism is so sacred. 3. Feral cats ARE wildlife. Can you pet them or pick them up? No. Do they hide from people? Yes. They're wild. They only look like pets. 4. The J Conservation Biol article is a review, not primary research, & I question its conclusions. Most feral cats aren't tested for FIV/FeLV, so how big a sample led to a quoted 5-12% infection rate in this population? As for diseases transmittable to humans, ferals hide from us, so how is disease getting transmitted? I could go on...

The concept of the U.S F&W Service becoming involved in the feral cat issue is chilling. Its procedures of poisoning, snaring, gassing, use of leghold traps and shooting have long been in question. Yet the Wildlife Service continues to waste taxpayer dollars killing wolves, mountain lions, geese, coyotes, foxes and thousands of other animals often as a subsidy for the livestock industry, Recently, the Service has been increasing its program to remove wildlife from urban areas. Notably, the organizer of the conference at which F&W employees will present papers regarding feral cats is The Wildlife Society which promotes removal of free-ranging cats and elimination of feral cat colonies. Education of the public regarding pet care, establishment of SPAY AND NEUTER CLINICS, encouraging pet owners to keep cats indoors for protection should be emphasized. There will always be abandoned animals in need of help. Killing is NOT the solution. Regulations should be established at a local level.

The massive outcry against the USFWS began because they deliberately killed native raccoons in their attempts to trap feral cats in the Keys. Only 3 feral cats were caught on refuge property; some 80 raccoons were trapped. With no science to justify their actions, this agency went rogue and killed the native wildlife it is supposed to protect.There are numerous invasive species which need to be addressed - feral pigs, Nutria, Zebra mussles, Lion fish. The destruction caused by the Zebra mussle alone is costing people billions of dollars.Prairie dog and wolf populations were decimated with implicit government approval, but wait, the nearly-extinct Black-Footed Ferret eats prairie dogs. Now, the USFWS is breeding the Ferrets, thanks to taxpayers. Wolves also have been reintroduced.USFWS wants to kill feral cats because they are the easiest target to address. They have no clue how to eradicate more harmful species which actually costs people money.Priorities need to change!

TNR is going to work, and it is going to please cat lovers and bird lovers alike. We can reduce the population because after being spayed/neutered, feral cats will die without reproducing. And, feral cat colonies that are being fed by caregivers are less likely to impact wildlife because they will already have their tummies full from the breakfast and dinner they are being given.

I am tired of this cat versus bird lover thing...why can't we acknowledge and respect ALL the species. There are other actions that we can take that will help all species that are more positive and healthy than killing off one species.

One more point...cats do not fit as easily into the invasive species category as opponents of TNR are saying. The reason...it is legal and encouraged to breed, adopt, and own a cat. So, we are not going to be able to ever get rid of them. Even if killing invasive species is an acceptable policy, cats do not fit into the category. Much of society want them to stay, and therefore we have to reinvent the rules for them. A new paradigm.

Kathleen and others, you are missing the point,feral cats are non-native, yes they are wild but they have not been part of the evolutionary process here in the U.S, therefore prey species are more vulnerable. Also, you can kill all the house sparrows and starlings you want, they are not protected by any fedral or state laws, same should apply to feral cats. Using the logic of feral cat supporters, I'm guessing that if we had lions or tigers roaming our our backyards that would be okay.

And yes, the J. of Conservation is a review, a review of the relevant information that is out there on this subject.

On another note, unless you are a Native American, does that mean your bags are packed.

Those opposed to TNR and feral cats have not adequately answered the question--how do you balance categorizing cats as an invasive species when they are also the second most popular pet in the country? The only way to get rid of the populations of feral cats would be to also ban cat ownership. I am curious what your feeling is about the killing of street dogs in places in Romania and Iraq. Based on your logic, you should be in support of this. It is just NOT as simple as people are saying. Each side accuses the other of not seeing the whole picture. The fact is we do not have all the information, and those who say they do are not being objective. What I know is that cats are not going anywhere, because they are pets (unless you want to promote the animal rights agenda of no ownership). BTW, Fish and Wildlife in Oregon is going to kill 2 wolves out of a pack of 4 because they are eating cattle. Large numbers of cattle are what is unnatural in this situation...not wolves needing to eat.

Steve, I think you’re missing the point by focusing on the number of birds killed annually by cats. Aggregate predation figures, such as those routinely used by ABC, USFWS, and others, invariably involve gross extrapolations from one habitat to another (e.g., conflating island populations with those on continents, rural and urban environments, etc.), combining common and rare bird species, healthy and unhealthy individuals, and so forth.

It’s an interesting twist on science, actually: instead of striving for increased certainty, the goal is to create an enormous—but essentially meaningless—“estimate.” In other words, this isn’t about science, but about marketing.

The USFWS has no policy on Feral Cats or TNR? But I'm looking at a letter from the U.S. Department of the Interior, Fish & Wildlife Service, that quite clearly contradicts your statement. http://www.abcbirds.org/abcprograms/policy/cats/pd.... This letter is from the USFWS to the Director of the NJ DEP, Division of Fish & Wildlife, stamped 11/20/09, reference #2010-TA-0038. The letter says, "The USFWS (Service) is writing to the (NJDFW) in support of the NJ Fish and Game Council’s Resolution on (TNR) and free-ranging domestic cats, passed June 19, 2007 (enclosed). The Service strongly opposes domestic or feral cats (Felis catus) being allowed to roam freely within the U.S. …the Service opposes TNR programs that allow return of domestic or feral cats to free-ranging conditions. …Further, the Service recommends that the State of New Jersey take action to eliminate feral cats throughout New Jersey.” Has the USFWS retracted this letter?

I don't follow the rationale of those who suggest cats should be allowed to roam free. To what purpose does it serve? It is indisputable that free-ranging cats kill wildlife. So, if you like cats in the wild, you must acknowledge the killing of wildlife associated with these cats. Can someone from the TNR crowd at least have the intestinal fortitude to admit as much? Until they do, there is NO possibility for rational discourse on this subject.

To No-Name and Wow, re-read my statement where I acknowledge that ferals kill birds. They just don't kill hundreds of millions. And the question isn't "allowing" them to roam; they've reverted to a wild state. The question is allowing them to live, as we allow the starlings and people to live. All three groups have been here so long, it's not smart to speak of returning the US to some idyllic "natural" ecosystem. We have to deal with the ecosystem we have, or what's left of it amid all the condo-building. Also those studies about FIV/FeLV prevalence were done on shelter cats with no indication of what % of the sample was feral. So how does Longcore figure they represent of all feral populations? Also, note this on Cornell's website: "In the US, approximately 2 to 3% of all cats are infected with FeLV. Rates rise significantly—13% or more—in cats that are ill, very young, or otherwise at high risk of infection." And DO read Peter's debunking of Longcore www.voxfelina.com/resources

Just a word about the dangers of putting all your stock in a single peer-reviewed article against TNR. The Lancet is one of the oldest and most venerable medical journals on the planet, and yet it took the editors 12 years (yes, years!) to give a full retraction of a deeply flawed study that causally linked measle-mumps-rubella vaccine with autism. In those 12 years, how many children were left unprotected against, all because of media hype based on one bit of bad science that somehow got into a top journal? According to the WHO, "Measles is one of the leading causes of death among young children." The author of the Lancet study, BTW, has had his medical license revoked; it was THAT bad. The lessons here are that good science gives reproducible results, and that some high-level scientists can let their egos get in the way and take a long time to admit that they made a mistake in believing conclusions based on faulty and even biased methodology (as was the case with the Lancet piece).

@Michael: Thank you for your reply. But if the NJ field office letter does not convey USFWS policy, can you please explain their statements? The letter clearly states, “The U.S. Fish and Wildlife Service (Service) is writing… The Service strongly opposes domestic or feral cats being allowed to roam… The U.S. Fish and Wildlife Service opposes TNR programs…” The letter can’t possibly be clearer. Either it is USFWS policy, or the local office is acting unethically in claiming it is. What action does the USFWS plan to take? Are rogue field offices not held accountable? It is one thing to claim that department members are acting on their own when they attend conferences and hold workshops as individuals that “happen” to work for USFWS. It is another thing entirely to claim that something written on Department of the Interior letterhead, referring to USFWS positions, does not reflect Department policy. If this is acceptable and does not violate Department policy, can you please explain why?

For some reason, some supporters of TNR programs feel that opponents to TNR are trying to ban pets as cats, which is ridulous. No one is trying to ban cats as pets, we just want owners to act responsibly. If you are a cat owner and claim to love your animals, keep them inside where it is safer and healthier for them and wildlife. In addition, please stop this ongoing practice of giving cats human qualities, "oh poor kitty wants be outside chasing sunbeams" give me break. The only thing kitty wants is to chase birds and other wildlife, and if given an opportunity, kill what it captures. And yes, birds do kill millions of birds annually. Pete said it best, with an estimated 60 million feral cats in the U.S, at least 60 million birds are being killed.

There seems to be some confusion with several of the the TNR folks providing comments on this thread reagarding the U.S Fish and Wildlife Service and the U.S. Department of Agriculture's Wildlife Services. These are two separate entities and in two completely different federal agencies. The U.S Fish and Wildlife Service, for the most part, is not in the business of removing or killing nuisance wildlife, that is the responsibility of USDA. Please get your facts straight before making any accusations. Such actions result in loss of credibility on your part.

Pete obviously doesn't know that there is no accurate estimate of the number of feral cats in the U.S. Credible estimates (numbers based on surveys, not a % of the pet cat population) range from 13M to 34M. Further, not all cats hunt birds:

- Coman & Brunner (1972) found that 92.5% of the 80 feral cats with food in their stomachs contained no bird remains;

- Liberg (1984) found that 31% of scat from house & feral cats collected over 3 years contained no vertebrate remains;

- Lepczyk et al. (2003) published that in the area surveyed in MI, 53% of outdoor cat owners reported that their cat(s) brought home no birds during the nesting season;

- Woods et al. (2003) found that 20% of 634 hunting cats studied across the U.K. from April-August of 1997 did not hunt birds.

Moller (2000) found evidence that cat predation is primarily compensatory, not additive.

Notably, there are approx 20 billion birds in the U.S. (John Trapp, wildlife biologist with USFWS for 33 years).

Sadly, man is the worst predator on this planet. Domestic cats are more likely to take down birds. The demise of songbirds is much more attributable to loss of habitat and climate change than feral cats. Flawed studies can promote many things, research needs to be done and not just hearsay. I have worked with feral colonies for 11 years and tnr does work; never found remains of birds, ever. Not saying it does not happen but I do not believe that ferals are directly responsible for killing birds.

Laurie, like you, my estimated population numbers came from published sources. Interesting references you listed, maybe you should have included the following and not just brief citations that fit your needs. All the authors (excluding Coman and Bruuner, which I will be getting later today) concluded that free roaming cats have negative impacts on wildlife. Woods (2000) concluded that 9 million cats in Great Britain killed brought home approximately 92.4 million animals, 27.1 million of which were birds. Liberg et al. (1984) found that free roaming/feral cats decimated rabbit/hare populations in a region of Sweden and began preying on smaller prey items such as mice, voles etc. which resulted in declines of native predators such as stoats, kestrels and long eared owls.Lepczyk et al. (2003)“In terms of management and conservation implications, our results, even taken conservatively, indicate that free ranging cats are killing a number of and wide range of bird species” Questions?

The citations listed were all studies of size on continents, not selected for content or outcome.

Liberg 1984 “It has been argued that cats, supported by humans, are more likely to affect prey populations than are natural predators…The present data do not justify a conclusive assessment of the effects of cats on their prey populations, but they indicate that cats by themselves were not limiting of any of their prey…as cats in this area did coexist with a number of other predators feeding on the same prey populations, their effects on the latter should be viewed in a total context…George 1974 argued that the most detrimental effect of cats on indigenous wildlife might be as competitors to native predators…This hypothesis gets some support from my study”

Cats were not limiting of the prey population. The theory of cats as prey gets “some support” from Liberg’s data.

And what of cats as prey themselves? George didn’t take that into consideration and cats have the fecundity of a prey species.

Woods 2003. “Our estimates of the total numbers of animals brought home by cats throughout Britain should be treated with requisite caution and these figures do not equate to an assessment of the impact of cats on wildlife populations.”